Quantitative Examination of a Perfusion Microscope for the Study of Osmotic Response of Cells

2004 ◽  
Vol 126 (4) ◽  
pp. 402-409 ◽  
Author(s):  
Hiroshi Takamatsu ◽  
Yuichi Komori ◽  
Sylwia Zawlodzka ◽  
Motoo Fujii
Keyword(s):  
Volume Change ◽  
Image Processing Technique ◽  
Hypertonic Solution ◽  
Isotonic Condition ◽  
Osmotic Response ◽  
Biological Studies ◽  
Rate Of Increase ◽  
Constant Rate ◽  
Nacl Concentration ◽  
Hypertonic Condition

The perfusion microscope was developed for the study of the osmotic response of cells. In this microscope, the cells are immobilized in a transparent chamber mounted on the stage and exposed to a variety of milieus by perfusing the chamber with solutions of different concentrations. The concentration of the supplied solution is controlled using two variable-speed syringe pumps, which supply an isotonic solution and a hypertonic solution. Before using this system to characterize the osmotic response of cells, the change in the concentration of NaCl solution flowing through the chamber is examined quantitatively using a laser interferometer and an image processing technique. The NaCl concentration is increased from an isotonic condition to a hypertonic condition abruptly or gradually at a given constant rate, and decreased from a hypertonic condition to an isotonic condition. It is confirmed that the concentration is nearly uniform in the cross direction at the middle of the chamber, and the change in the NaCl concentration is reproducible. The average rate of increase or decrease in the measured concentration agrees fairly well with the given rate when the concentration is changed gradually at a constant rate. The rate of the abrupt change is also determined to be the highest limit achieved by the present method. As the first application of using the perfusion microscope for biological studies, the volume change of cells after exposure to a hypertonic solution is measured. Then, the hydraulic conductivity of the cell membrane is determined from the comparison of the volume change between the experiment and the theoretical estimation for the measured change in the NaCl concentration of the perfused solution.

scholarly journals Stemflow in a Multi-storied Aspen Community

1972 ◽  
Vol 2 (2) ◽  
pp. 160-165 ◽  
Author(s):  
John R. Clements
Keyword(s):  
Marked Effect ◽  
Forest Stand ◽  
Forest Community ◽  
Canopy Layer ◽  
Rate Of Increase ◽  
Constant Rate ◽  
Mathematical Equations

This paper presents mathematical equations describing the relationships between the amount of stemflow per canopy layer per storm and the amount of gross rain per storm for four different canopy layers in a multi-storied forest community. The curves representing the relationships were curvilinear; for three of the canopy layers stemflow per storm increased at an increasing rate as gross rain per storm increased, approaching a constant rate of increase. Numerical values of the equation coefficients varied with canopy level in the forest stand profile and with variations in vegetal structure within the forest community. The lowest canopy in the vegetal profile, a fern canopy, had the most marked effect on rainfall redistribution.

scholarly journals QUANTITATIVE ASPECTS OF THE MULTIPLICATION OF INFLUENZA A VIRUS IN THE MOUSE LUNG

1952 ◽  
Vol 95 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Harold S. Ginsberg ◽  
Frank L. Horsfall
Keyword(s):  
Infected Mouse ◽  
Influenza A Virus ◽  
Influenza A ◽  
Fold Increase ◽  
Mouse Lung ◽  
Quantitative Investigation ◽  
Pulmonary Lesions ◽  
A Value ◽  
Rate Of Increase ◽  
Constant Rate

Influenza A virus, PR8 strain, increases in amount in the infected mouse lung at a relatively constant rate. When more than 25 M.S.50 doses of virus is inoculated, the rate of multiplication appears to be independent of the amount of virus introduced; has a value of 1,100-fold increase per day. The rate of increase in the pulmonary lesions induced by infection of the mouse lung with PR8 also appears to be relatively constant and independent of the amount of virus inoculated; has a value of 8.5-fold increase per day. The essential variables in the PR8-mouse lung system appear to be equated satisfactorily by functions which were derived previously (4) during a similar quantitative investigation on pneumonia virus of mice (PVM). Evidence in support of the hypothesis that the processes of multiplication of PR8 and PVM are different in the mouse lung is presented.

scholarly journals Cytosolic inositol 1,4,5-trisphosphate dynamics during intracellular calcium oscillations in living cells

2006 ◽  
Vol 173 (5) ◽  
pp. 755-765 ◽  
Author(s):  
Toru Matsu-ura ◽  
Takayuki Michikawa ◽  
Takafumi Inoue ◽  
Atsushi Miyawaki ◽  
Manabu Yoshida ◽  
...  
Keyword(s):  
Metabotropic Glutamate Receptor ◽  
Living Cells ◽  
Calcium Oscillations ◽  
Spike Generation ◽  
Metabotropic Glutamate ◽  
Endogenous Histamine ◽  
Rate Of Increase ◽  
Constant Rate ◽  
Inositol 1,4,5 Trisphosphate ◽  
Stimulation Of

We developed genetically encoded fluorescent inositol 1,4,5-trisphosphate (IP3) sensors that do not severely interfere with intracellular Ca2+ dynamics and used them to monitor the spatiotemporal dynamics of both cytosolic IP3 and Ca2+ in single HeLa cells after stimulation of exogenously expressed metabotropic glutamate receptor 5a or endogenous histamine receptors. IP3 started to increase at a relatively constant rate before the pacemaker Ca2+ rise, and the subsequent abrupt Ca2+ rise was not accompanied by any acceleration in the rate of increase in IP3. Cytosolic [IP3] did not return to its basal level during the intervals between Ca2+ spikes, and IP3 gradually accumulated in the cytosol with a little or no fluctuations during cytosolic Ca2+ oscillations. These results indicate that the Ca2+-induced regenerative IP3 production is not a driving force of the upstroke of Ca2+ spikes and that the apparent IP3 sensitivity for Ca2+ spike generation progressively decreases during Ca2+ oscillations.

scholarly journals KAJIAN TINGKAT KERUSAKAN PENCEMARAN DI SUNGAI KRUKUT

2020 ◽  
Vol 26 (2) ◽  
pp. 11-30
Author(s):  
Yuni Sesempuli ◽  
◽  
Bambang Iswanto ◽  
Diana Irvindiaty Hendrawan ◽  
◽  
...  
Keyword(s):  
River Discharge ◽  
Degradation Rate ◽  
The Self ◽  
Load Management ◽  
Precipitation Process ◽  
Settling Rate ◽  
Rate Of Increase ◽  
Constant Rate ◽  
Standard Value ◽  
A Current

Abstract. The population growth with its activities causes pressure on the Krukut River. Load management of pollutants that enters the river is based on the self purification of the river. This study aims to analyze the river characteristics and degradation rate of Krukut River. Krukut River which is a research location has a length of ± 9.04 km. Characteristics of Krukut River has a type of small rocky riverbed and irregular with manning coefficient from 0.035 to 0.045. The depth ranging from 0,99 - 2 m, with a current velocity from 0,3 to 1,29 m/s. Krukut River discharge at 2,873-7,889 m3/sec. Streeter Phelps modeling to find out the constant rate of degradation of Krukut River which resulted in the value of DO and BOD. The rate of increase of dissolved oxygen (Ka) with the value of Ka range of 1,586-4,542 d-1, the standard value should be 1,494 d-1. The results of degradation rate (Kd) of the study obtained values range 0,285–0,394 d-1 with a default value of 0,501 d-1. For a settling rate (Ks) the range of 0,070 d-1 –0,096 d-1 with a standard value should be 0,751 d-1 which means the precipitation process is quite slow. Keywords: pollution degradation rate, Krukut River, Streeter Phelps methode, selfpurification, water quality

scholarly journals Recent volume and area changes of Kaskawulsh Glacier, Yukon, Canada

2011 ◽  
Vol 57 (203) ◽  
pp. 515-525 ◽  
Author(s):  
Norah Foy ◽  
Luke Copland ◽  
Christian Zdanowicz ◽  
Mike Demuth ◽  
Chris Hopkinson
Keyword(s):  
Satellite Imagery ◽  
Volume Change ◽  
Aerial Photography ◽  
Airborne Lidar ◽  
Ablation Zone ◽  
Constant Rate ◽  
Lidar Measurements ◽  
Historical Aerial Photography ◽  
Elevation Changes ◽  
Air Photo

AbstractRecent surface elevation changes of Kaskawulsh Glacier, Yukon, Canada, are quantified by comparing an air-photo derived DEM from 1977 and airborne lidar measurements from 1995, 2000 and 2007. Surface-area changes are assessed using historical aerial photography from 1956 and satellite imagery from 1977 to 2007. Combined, these measurements provide some of the first detailed records of volume change of a large Yukon glacier. Between 1977 and 2007, Kaskawulsh Glacier underwent a decrease in area of 1.53% and a decrease in volume of 3.27–5.94 km3 w.e.). The terminus also retreated by 655 m over the period 1956–2007. There was relatively minor volume change over the period 1977–95 (<+0.01 km3 w.e.a−1), while over the periods 1995–2000 and 2000–07 volume losses occurred at a relatively constant rate of −0.51 and −0.50 km3 a−1 w.e., respectively. Since 1995, thinning has been prominent throughout the ablation zone, while relative stability and even slight thickening has occurred in the accumulation zone. These findings are similar to those recently observed at other nearby Alaskan glaciers.

Blood Pressure and Ageing; Results of a 15–17 Year Follow-Up Study in South Wales

1973 ◽  
Vol 45 (s1) ◽  
pp. 23s-33s ◽  
Author(s):  
W. E. Miall ◽  
Susan Chinn
Keyword(s):  
Blood Pressure ◽  
Linear Regression ◽  
Exponential Function ◽  
Blood Pressure Level ◽  
Rate Of Change ◽  
South Wales ◽  
Epidemiological Surveys ◽  
Rate Of Increase ◽  
Constant Rate ◽  
Aged Subjects

1. Several recent studies of the relation between blood pressure and ageing have been re-examined, and it is concluded that none satisfactorily investigates the possibility of separate influences of age and attained pressure in determining the rate of change of pressure with time. 2. If the rate of increase of pressure is proportional to the attained pressure, pressure is an exponential function of age. An attempt has been made to determine the relation of blood pressure with age by fitting curves to individuals' measurements made over periods of 15 1/2 and 17 1/2 years in two epidemiological surveys in South Wales. 3. Three models were used: (1) a linear regression, (2) an exponential function, and (3) a model based on the hypothesis that an individual's pressure fluctuates about a constant mean until a variable age at which it increases at a constant rate. Neither model (2) nor model (3) was significantly better than model (1), but this may have been largely due to the small number of measurements (four) for each subject. 4. A positive slope to the linear regression of pressure on time was obtained for most adults. In middle-aged subjects the distributions of these regression coefficients appear unimodal. The rate of increase was higher in those with initially raised values but increased with age independently of the blood pressure level. In these populations some factor related to ageing appears to play a rôle in causing this increase in pressure in addition to any possible direct influence of the attained pressure.

Regulation of V2R transcription by hypertonicity and V1aR-V2R signal interaction

2008 ◽  
Vol 295 (4) ◽  
pp. F1170-F1176 ◽  
Author(s):  
Yuichiro Izumi ◽  
Yushi Nakayama ◽  
Hasiyet Memetimin ◽  
Takeaki Inoue ◽  
Yukimasa Kohda ◽  
...  
Keyword(s):  
Promoter Region ◽  
Promoter Activity ◽  
Urine Volume ◽  
Renal Medulla ◽  
Urine Concentration ◽  
Isotonic Condition ◽  
Intracellular Ca ◽  
Hypertonic Condition ◽  
V2 Receptor ◽  
Vasopressin V1a Receptor

Arginine vasopressin (AVP) and hypertonicity in the renal medulla play a major role in the urine concentration mechanism. Previously, we showed that rat vasopressin V2 receptor (rV2R) promoter activity was increased by vasopressin V2R stimulation and decreased by vasopressin V1a receptor (V1aR) stimulation in a LLC-PK1 cell line stably expressing rat V1aR (LLC-PK1/rV1aR). In the present study, we investigated the effects of hypertonicity on the rV2R promoter activity and on the suppression of rV2R promoter activity by V1aR stimulation in LLC-PK1/rV1aR cells. rV2R promoter activity was increased in NaCl- or mannitol-induced hypertonicity. The hypertonicity-responsive site in the rV2R promoter region was limited to 10 bp, including the Sp1 motif. The increase of V2R promoter activity by hypertonicity was significantly inhibited by a JNK inhibitor (SP600125) and PKA inhibitor (H89). In contrast, rV2R promoter activity was remarkably suppressed by V1aR stimulation in the hypertonic condition rather than in the isotonic condition. The AVP-stimulated intracellular Ca2+ concentration was increased in the hypertonic condition, suggesting the functional activation of V1aR by hypertonicity. In conclusion, 1) V2R promoter activity is increased by hypertonicity via the JNK and PKA pathways, 2) suppression of V2R expression by the V1aR-Ca2+ pathway is enhanced by hypertonicity, and 3) hypertonicity enhances the V1aR-Ca2+ pathway. The counteractivity of V2R and V1aR could be required to maintain minimum urine volume in the dehydrated state.

scholarly journals Grain Coarsening of Water-Saturated Snow

1979 ◽  
Vol 22 (86) ◽  
pp. 83-105 ◽  
Author(s):  
Charles F. Raymond ◽  
Katsutosi Tusima
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Melting Temperature ◽  
Grain Size Distribution ◽  
Exchange Process ◽  
Particle Surface ◽  
Relative Size ◽  
Solid Mass ◽  
Rate Of Increase ◽  
Constant Rate

AbstractExperimental measurements were made of changes in grain-size distribution with time in snow saturated with solutions of various impurity contents. Qualitatively, the changes in grain-size distribution occur by shrinkage and eventual disappearance of the relatively small particles and growth of the relatively large particles by a solid mass-exchange process which conserves the total solid mass. The distribution of relative grain size is found to be essentially time independent except for transient effects lasting only several to several tens of hours after the time of initial saturation. Mean grain volume increases at a constant rate, which for solutions of impurity concentration less than about 0.01 mol 1–1is (5 to 6) X 10–3mm3h–1. In pure solutions the smallest particles shrink at a characteristic rate of about 1 x 10–2mm3h–1. Once the steady relative-size distribution is established, the rate of volume change of typical grains varies linearly with grain volume from the characteristic negative rate for the smallest particles through zero for particles of mean volume to positive values for particles of larger volume. The basic features of the changes that take place are explained in terms of heat-flow controlled melting and freezing determined by temperature differences associated with the effect of particle surface curvature on melting temperature. The constant rate of increase of mean grain volume is a consequence of conservation of total ice volume. The expectation that particles of intermediate size would be neither shrinking or growing leads to the conclusion that the actual rate of increase in mean grain volume is about one-half the characteristic melting rate of the smallest particles, which fits the observations. The process of grain growth is slowed by impurities in a way which can be predicted from the melting-temperature depression caused by the impurity and its diffusion coefficient. The transport of heat between grain surfaces is largely through the liquid-filled gaps between them, but about 19% is conducted through the solid.

Urea formation in nephrectomized mice

1960 ◽  
Vol 198 (6) ◽  
pp. 1271-1273
Author(s):  
Paul F. Fenton ◽  
Catherine Vakirtzi-Lemonias
Keyword(s):  
Oral Administration ◽  
Intravenous Administration ◽  
Hypertonic Solution ◽  
Protein Catabolism ◽  
Protein Sparing ◽  
Rate Of Increase

The rate of increase of blood urea levels in nephrectomized mice has been studied under a variety of conditions which might influence protein catabolism. Oral administration of substantial amounts of carbohydrates or intravenous administration of 5% glucose led to an increased rate of urea accumulation. The intravenous administration of 20% glucose slowed the rate of urea increase. However, this apparent protein-sparing action could be simulated by the administration of a hypertonic solution of sorbitol.

Osmotic regulation of vasopressin and oxytocin release is rate sensitive in hypothalamoneurohypophysial explants

1990 ◽  
Vol 258 (2) ◽  
pp. R492-R500 ◽  
Author(s):  
C. Yagil ◽  
C. D. Sladek
Keyword(s):  
Culture Medium ◽  
Significant Inhibition ◽  
Rate Of Change ◽  
Osmotic Regulation ◽  
Peak Response ◽  
Rate Of Increase ◽  
Nacl Concentration ◽  
Oxytocin Release

Explants of the hypothalamoneurohypophysial system (HNS) from rats were maintained in perifusion culture and exposed to 15-18 mosmol/kgH2O changes in the osmolality of the culture medium achieved by increasing or decreasing the NaCl concentration. The rate of change in osmolality was either 0.14 +/- 0.01 mosmol/min (2%/h), 0.27 +/- 0.02 mosmol/min (5%/h), or 1.7 +/- 0.2 mosmol/min (30%/h). Vasopressin (VP) and oxytocin (OT) release into the culture medium was determined. Increased VP release was detected after all three rates of increase, but the peak response occurred sooner and in response to a smaller increment in osmolality during the 5% rate of increase compared with the 2% rate of increase. Peak VP release occurred during the first 10 min of the 30% pulse and was significantly greater than the response to the 2 and 5% rates (P less than 0.05). The increase in VP release was sustained throughout the 3 h of hypertonicity during the 2% pulse, but not during the 5 and 30% osmotic pulses. A significant decrease in VP release was observed on returning the osmolality to basal at both the 2 and 5% rate, but this inhibition was followed by a rebound in VP release that started during the decrease in osmolality and significantly exceeded basal VP release. A significant inhibition of VP release also was observed when explants were exposed to hypotonic pulses at the 2 and 5% rate. At both rates, the inhibition of VP release corresponded to a 5- to 7-mosmol/kgH2O decrease in osmolality.(ABSTRACT TRUNCATED AT 250 WORDS)

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